Filters for Cigarettes, Pipes, and Cigars and Related Products

ABSTRACT

A filter media containing continuous nanofiber or submicron fiber having low air resistance that that can be incorporated into cigarettes, cigarette attachments, pipes, and cigars. The media may formed in circular or cylindrical shapes and is comprised of thin, flexible fabric forms that can be cut and fit into the body or cavity of cigarettes, cigarette attachments, pipes, cigars, and other tobacco related products and incorporates a nanofiber or submicron fiber coating creating an interfiber spacing between 1.0 to 2.0 μm, preferably between 1.2 and 1.5 μm.

FIELD OF THE INVENTION

This invention relates to the design and application of advanced filter media, and, more specifically to filter media containing continuous nanofiber or submicron fiber for cigarettes and other inhalable tobacco products.

BACKGROUND OF THE INVENTION

Tobacco products have been produced and consumed around the world for thousands of years. In spite of numerous health risks, the World Health Organization estimates that there are almost a billion tobacco users worldwide, the majority of which are smokers, i.e., users of an inhalable tobacco product. One of the primary purposes of smoking tobacco products is to inhale nicotine. Nicotine may provide mental stimulation or other perceived benefits. Nicotine is also addictive; continued use of tobacco products tends to result in reliance on a continuing source of the substance.

It is generally accepted that various components in cigarettes and other tobacco products are responsible for the health risks associated with the use of these products. However, tar or tars in cigarettes, pipes, cigars, and other tobacco related products are known to cause numerous health problems, including staining of teeth, gum disease, tongue inflammation and cancer, respiratory disorders, and lung cancer. Because of the known health problems, tobacco related products are required by law to post a warning on the packaging that it may cause lung cancer.

Aside from actually reducing the tar content in the smokable component of the tobacco product, the principle means of preventing tar inhalation, and thereby reducing one's health risks, is though filtration. Most conventional cigarettes do incorporate a filter of some sort; however, it is of a very low efficiency. Indeed, these “standard” filters serve more to provide a pleasant sensation or feel for the lips of the smoker. The tar capturing efficiency of these “standard” filters is generally rather poor. Cigarette attachments, i.e., attachable filters, are occasionally used to further reduce the tar content. While these attachments do have at least a minimal capability to filter and trap tar, their designs are based on temperature differentiation without using a filter media. This design is inherently less productive than direct filtering. Pipes use a slightly varied method to filter and capture tar. Pipes rely upon a paper-type filter wrapped with a plastic inside the pipe. The efficiency of this mechanism is also very low. Interestingly, cigars do not have any filter or devices to prevent tar within the cigar from reaching the smoker.

Filter means which filter or trap a substantial amount of tar have been disclosed in the prior art but the heavy filtering required to accomplish this end comes with a price. In order to accomplish this desired level of filtration, the flow of air through the filter must be severely restricted as well. As a result, smokers tend to avoid using these dense filters or products incorporating them as they make the use of the cigarette or tobacco product less desirable.

To overcome the health problems associated with inhaled tar, a new product referred to as an electronic cigarette or e-cigarette has been developed in recent years. This product imitates the shape of a cigarette and contains nicotine but no tobacco. A user of the product, probably best described as an “inhaler” rather than the conventional term of “smoker”, inhales nicotine without “smoke” in the inhaled air. As a result, the e-cigarette is a tar free product. However, a significant, and frequently pivotal, drawback is that it does not have the tobacco taste and odor which most smokers' desire.

In spite of the known deleterious health effects of tar inhalation from using tobacco products, there are no highly efficient filters/devices to prevent this tar from entering smokers' internal organs. This is likely due, at least in part, to the small size of nicotine particles, 0.9 μm-1.0 μm. Conventional filter technologies cannot capture tar while allowing nicotine to pass through in a cost effective and low resistant manner. The instant invention presents a solution to the foregoing problems.

OBJECT OF THE INVENTION

It is therefore an object of the invention to provide a filter media that can be easily used or incorporated into a wide range of tobacco products and is highly effective at filtering inhaled tar for a user of such products.

It is a further object of the invention to provide a filter media that offers a low inhalation air resistance while providing effective filtration.

It is a further object of the invention to provide a filter media that permits a sufficient amount of nicotine to pass through unhindered so as not to impinge a user's enjoyment of such a tobacco product.

SUMMARY OF THE INVENTION

This invention is a filter media containing continuous nanofiber or submicron fiber that that can be incorporated into cigarettes, cigarette attachments, pipes, and cigars which is able to filter fifty to one hundred percent of all inhaled tar and yet permits more than sixty percent of the inhaled nicotine to pass through. The media may be formed in circular or cylindrical shapes and is comprised of thin, flexible fabric forms that can be cut and fit into the body or cavity of cigarettes, cigarette attachments, pipes, cigars, and other tobacco related products. The filter media has a low air resistance, similar to current cigarette filters, but is an order of magnitude better in capturing tar contained in the tobacco products.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a circular shape filter prepared by die cutting of a nanofiber coated fabric in accordance with the present invention.

FIG. 2 is a design of a cigarette filter in accordance with the present invention.

FIG. 3 is an alternate design of a cigarette filter in accordance with the present invention.

FIG. 4 shows the preparation of a cylindrical shape filter in accordance with the present invention.

FIG. 5 is a cigarette attachment containing circular shape filters in accordance with the present invention.

FIG. 6 shows cigarettes containing circular or cylindrical shape filters in accordance with the present invention.

FIG. 7 is a pipe containing a cylindrical shape filter in accordance with the present invention.

FIG. 8 shows cigars containing cylindrical shape filters in accordance with the present invention.

FIG. 9 shows the application of a filter in accordance with the present invention in use in a designated smoking room.

DETAILED DESCRIPTION

The instant invention is an advanced filter media for cigarettes, cigarette attachments, pipes, cigars, and other similar products. This filter media can be controlled to capture between 50% to 100% of tar while allowing more than 60% of the nicotine to pass through to the smoker. The filter media also features low air resistance thereby enhancing its appeal to a smoker.

The filter media is fabricated from nanofiber or submicron fiber coated fabrics (conventional nonwoven filter media). The nanofiber or submicron fiber coating creates interfiber spacing between 1.0 to 2.0 μm, preferably between 1.2 and 1.5 μm. This range of interfiber spacing can capture most of the tar while still allowing nicotine to pass through.

Continuous nanofibers can be manufactured by an electrospinning technique as disclosed in co-pending U.S. patent application Ser. No. 12/655,227. Because of the ultrafine diameter of these nanofibers the above-referenced range of interfiber spacing can be created with a very small amount of solid fiber among them. This architecture results in low air resistance. Fiber media with submicron fiber can achieve a similar goal but with higher air resistance. Micron size fibers with similar particle (tar) capturing efficiency would result in much higher air resistance. Further, much larger fiber volume is needed resulting in a bulky design which is unattractive to users. In addition, micron size fibers or porous materials do not allow any significant control over the size of particles to be captured versus those which may be permitted to pass through the filter.

For cigarette, pipe, and cigar filter applications a design must be selected that generally only captures particles larger than 1.1 μm in size. Since nicotine particles are, on average, between 0.9 and 1.1 μm, these particles should pass through the instant filter media unhindered. Experimental results indicated that the filters disclosed herein capture a great majority of all the tar contained in the cigarettes, pipes, and cigars.

Two different shapes of filters have been developed as filters for cigarettes, pipes, and cigars. The first embodiment is cut into circular or near-circular shapes to fill in the cross section of the cigarettes, pipes, and cigars. A second embodiment is cylindrical and is created by rolling up the filter media into an appropriate length and a certain diameter and attaching it at one end of the cigarette or cigar. Since a pipe is typically split into two or more pieces and joined near the middle of the length section, the rolled-up filter of the second embodiment can be conveniently inserted into the pipe cavity at the joint area.

Filters fabricated with various grades of nanofiber coated fabrics were tested and it was determined that certain grades have excellent tar capturing efficiency, allowing nicotine to pass through, offering low resistance to smoke, and allowing smokers to satisfactorily smell and taste the tobacco.

As shown in FIG. 1, a sheet of nanofiber coated fabric 10 comprises a conventional fiber media 11 manufactured from micron size fibers and a continuous nanofiber coating 12. The nanofiber coated fabric can be prepared in a single sheet or a stack of multiple sheets for the preparation of filters for cigarettes, cigarette attachments, pipes, cigars, and other tobacco related products. A die cutter 13 can be used to punch filters with the correct diameter that fits cigarettes, cigarette attachments, pipes, cigars, and other tobacco related products. The permutation of the nanofiber coating and the fabric can be arranged in FIG. 2 as nanofiber/fabric/nanofiber/fabric with one or more sets. Alternatively, it can be designed as fabric/nanofiber/nanofiber/fabric, as seen in FIG. 3, with one or more sets. Another alternative is to combine these two designs in one.

In tobacco related filter applications, the fabric's main function is to provide support to the nanofiber rather than capturing particles as a great majority of the particles involved are very small. The tar and smoke can pass through the fabric (conventional filter media without nanofiber coating) freely. Continuous submicron fibers can be produced via a melt spinning technique. When submicron fibers are used the fabric (conventional filter media) would not be needed. However, the air resistance of the filters produced would be higher than the filters (FIGS. 2 and 3) using nanofibers. It also requires a larger volume of fibers to achieve the desired tar capturing efficiency. These circular shape filter media will be inserted into one end of the cigarettes (cigarette attachments use the same diameter as cigarettes), pipes, and cigars and wrapped up with the cover paper.

Another embodiment of the filter design is formed from nanofiber or submicron fiber coated fabric rolled-up into appropriate diameters and cut it into appropriate lengths for use in cigarettes, cigarette attachments, pipes, cigars, and other tobacco related products. These products require filters with different diameters and lengths to fit their designs. As shown in FIG. 4 a sheet of nanofiber coated fabric 41 is rolled up into a cylindrical form 40. A filter in cylindrical form with different diameters and lengths is required to fit into the bodies of cigarettes, the cavities of pipes, and the bodies of cigars.

In this invention the diameter of the “nanofiber” ranges from 2 nm to 5 μm, preferably in the range of 10 nm to 800 nm. The polymers used for the manufacturing of the nano and submicron fibers include, but are not limited to, Polyvinylidene fluoride, or polyvinylidene difluoride (PVDF), polyacrylonitrile (PAN), polyphenylene sulfide (PPS), polyetheretherketone (PEEK®), poly(etherketoneketone) (PEKK®), polysulfone, polyethylene (PE), polyetheremide (ULTEM®), polypropylene (PP), polyethersulfone, polycarbonate, poly(methyl methacrylate) (PMMA), polystyrene, polyurethanes (PU), polycarbonate, polyethersulfone, polyisocyanurate (PIR), polyetheremide (PEI), shape memory polymers (SMP), nylon, and polyethylene. Any nontoxic polymers that can be spun into nanofibers or melt spun into submicron fibers may be used for the manufacturing of the filters for cigarettes, cigarette attachments, pipes, cigars, and other tobacco related products.

Filter media having particular characteristics is incorporated into this invention so as to enable the features and benefits taught herein. As a result of the low air resistance, no additional effort need be made by a smoker to achieve the filtering, and commensurate health, benefits.

Example 1

Cigarette attachments were obtained from Zhejiang Sanda Smoking Sets Co. Ltd. A Marlboro Medium cigarette was inserted into the cigarette attachment and a smoking machine was used to do the smoking test. The weights of the cigarette attachment before and after the smoke test were 0.9026 g and 0.9278 g, respectively. The weight gain of the cigarette attachment (mainly tar) is 0.0252 g.

A cigarette filter containing four layers of nanofiber coated fabrics in accordance with the teachings found herein was then prepared. The prepared filter was then inserted into the cavity of the cigarette attachment. Smoking was performed using the same kind of cigarette, cigarette attachment, and smoking machine. The weight gain of the cigarette attachment was 0.8654 g and 0.9086 g, respectively. The weight gain of the cigarette attachment with the instant filter is 0.0432 g. which is 71.4% higher than the one without our filter. Thus, the instant filter for cigarette attachment with four layers of nanofiber coated fabric captured 71.4% of tar more than the one without the instant filter.

It will further be noted that the use of several additional layers of nanofiber coated fabric did not noticeably increase the weight gain of the filter. This indicates that the majority of the tar in the cigarette has been captured.

Example 2

A pipe manufactured by Missouri Meerschaum Co. and pipe tobacco were purchased for testing. The pipe, as purchased, had a paper type filter wrapped with a plastic film. The weight of the tobacco used for each test was 0.7057 g. The weights of the filter before and after the smoking test using our smoking machine were 0.4727 g and 0.4984 g, respectively. The weight gain was 0.0257 which included tars and some moisture (contained in the tobacco).

Referring now to FIG. 4, a pipe filter in cylindrical form, which had the same length and diameter as the original filter which came with the pipe, was prepared in accordance with teachings found herein. The same amount of tobacco and same smoking machine were used for a subsequent test. Following a second smoking test, the weights of the nanocomposite filter before and after the smoking test using the smoking machine were 0.1643 g and 0.3790 g, respectively. The weight gain was 0.3091 g which, again, included tar and some moisture (contained in the tobacco).

The nanocomposite filter of the instant invention was about ten times more efficient than the conventional filters that are currently used in pipes. After the filter was dried, the weight gain was determined to be 0.1448 g (tar) which was principally tar.

Example 3

A pack of Dutch Masters cigars was purchased for testing. These cigars typical in that they do not contain any filter. However, a filter was prepared containing four layers of nanofiber coated fabric as shown in FIG. 3 and attached to a Dutch Master cigar. The cigar and filter were placed in the cavity of a smoking machine. The weights of the prepared filter before and after the smoking test using our smoking machine were 0.1196 g and 0.2838 g, respectively. The weight gain of the filter was 0.1642 g, which is mainly tar.

Example 4

Various test results confirm the efficiency and other benefits of the filter media disclosed herein. Marlboro Medium cigarettes were purchased, in conventional fashion, for testing. Referring to FIG. 1, cylindrical form filters were prepared with several different grades of nanofiber coated fabrics. The filters were rolled up into diameters about 0.312-in and 1.125-in long. These particular dimensions are the dimensions for the current filters found at one end (inhalation end) of the Marlboro Medium cigarettes. The original cigarette filter was removed and was replaced with the instant filter. A smoking test was conducted using a smoking machine.

The weights of the instant filter before and after the smoking test were 0.1141 g and 0.1592 g, respectively. The filter captured all of the smoke (the air passing thru the smoking machine is free of smoke) and tar (no tar passed through). The weight gain of the filter was 0.0451 g, which was mainly tar.

A cigarette filter was then prepared using another grade of nanofiber coated fabric. The weights of this filter before and after the smoking test using our smoking machine were 0.1242 g and 0.1588 g, respectively. The weight gain in this case was 0.0346 g, which, again, was mainly tar. A small amount of smoke passed through the smoking machine indicating that a very small amount of tar passed through the filter. When tested by an actual smoker, the smoker enjoyed the feel, taste, and smell of the cigarette despite the fact that it incorporated the nanofiber filter.

Example 5

Prototype filters were fabricated in both circular forms, as seen in FIGS. 2 and 3, and cylindrical forms. These prototype filters were then incorporated into various products: A circular shape filter 101 was fabricated and inserted into the cavity of a cigarette attachment 100 as shown in FIG. 5. A thin paper was used to wrap the filter 201 to the body of the cigarette 200 (in this case, Marlboro Medium and Paul Mall cigarettes) as shown in FIG. 6. A prototype filter 301 for pipe 300 is shown in FIG. 7. And finally, a cylindrical filter 401 is attached to one end of a cigar 400 and wrapped with a thin paper as shown in FIG. 8.

Example 6

The filter media disclosed herein may also be used in other applications. For example, it may be used in the filtration system of a public smoking area. In this example, the nanofiber coated filter media is used as the filter for a designated smoking room 500 in a public facility. A ventilation system located at or in the ceiling of the room would draw the smoke up so that people inside the room do not have to experience a “smoky” environment. The ventilation system and the filter 504 are sealed with elastomeric gaskets to prevent smoke from leaking out. The smoke and the odor are captured by the filter so that the air exiting the smoke designated room, via the ventilation system, is fresh and clean. In addition, the filtration system, reduces the smokers 501 exposure to second-hand cigarette smoke 502 or 503 within the room itself 500.

As the invention has been described herein, it will be apparent to those skilled in the art that the invention may be varied in certain ways without departing from the spirit or the scope of the invention. Any and all such modifications are intended to be included with the scope of this invention and the claims found herein. 

What is claimed is:
 1. A filter for inhalable tobacco products comprising at least one nanofiber coated fabric.
 2. The filter of claim 1 wherein said filter is either circular or cylindrical in shape.
 3. The filter of claim 2 wherein said filter has an interfiber spacing between 1.0 μm to 2.0 μm.
 4. The filter of claim 3 wherein said interfiber spacing is between 1.2 μm and 1.5 μm.
 5. The filter of claim 3 wherein said inhalable tobacco products consist of one of the group of cigarettes, cigars, and pipes.
 6. The filter of claim 5 wherein said filter is able to capture at least 50% of the tar passing therethrough and allowing over 60% of nicotine to pass through.
 7. The filter of claim 6 wherein said filter captures 50% to 100% of the tar passing therethrough.
 9. A circular or cylindrical shape filter for cigarettes containing at least one nanofiber coated fabric.
 10. The filter of claim 8 wherein the cylindrical shape filter is prepared by rolling up one or more sheets of nanofiber coated fabrics.
 11. The filter of claim 9 wherein the coated fabric includes sub-micron fibers.
 12. The filter of claim 9 wherein said nanofibers are continuous and have diameter ranges from 2 nm to 5 μm, preferably in the range of 10 nm to 800 nm.
 13. The filter of claim 11 wherein said nanofiber coating creates interfiber spacing between 1.0 μm to 2.0 μm, preferably between 1.2 μm and 1.5 μm.
 14. The filter of claim 13 wherein said filter captures between 50% to 100% of the tar passing therethrough and allows over 60% of nicotine to pass through.
 15. The filter of claim 11 wherein said submicron fiber coating creates interfiber spacing between 1.0 to 2.0 μm, preferably between 1.2 and 1.5 μm.
 16. The filter of claim 15 wherein said filter captures between 50% to 100% of the tar passing therethrough and allows over 60% of nicotine to pass through.
 18. A cylindrical shape filter for pipes containing one or multiple nanofiber coated fabrics having low air resistance and interfiber spacing between 1.0 to 2.0 μm.
 19. The filter of claim 18 wherein said the cylindrical shape filter is prepared by rolling up one or more sheets of nanofiber coated fabrics.
 20. The filter of claim 19 wherein said coated fabrics include submicron fibers.
 21. A filter comprising at least one nanofiber coated fabric having interfiber spacing between 1.0 μm and 2.0 μm and a ventilation system whereby said ventilation system and filter may be used to remove the smoke and associated tar components of smoke in a room. 